Thread: need some help on link lists using stacks...

no errors and warnings...but dowanna accaept input... ...and i'm totally confused..can someone help me repair this codes...

Code:

#include <stdio.h>

#include <stdlib.h>



struct stackNode {

   char data;

   struct stackNode *nextPtr;

};



typedef struct stackNode StackNode;

typedef StackNode *StackNodePtr;



void push( StackNodePtr *, int );

int pop( StackNodePtr * );

int isEmpty( StackNodePtr );

void printStack( StackNodePtr );

void instructions( void );



int main()

{ 

   StackNodePtr stackPtr = NULL;

   int choice;

   char value[20];

 

 instructions();

 printf( "? " );

 scanf( "%d", &choice );



   while ( choice != 3 ) { 



      switch ( choice ) { 

         case 1:

            printf( "Enter a student name: " );

			fflush(stdin);

            gets(value );

            printStack( stackPtr );

            break;

         case 2:

            if ( !isEmpty( stackPtr ) )

               printf( "The deleted name is %s.\n", 

               pop( &stackPtr ) );

			   printStack( stackPtr );

            break;

         default:

            printf( "Invalid choice.\n\n" );

            instructions();

            break;

      }



      printf( "? " );

      scanf( "%d", &choice );

   }



   printf( "End of run.\n" );

   return 0;

}



void instructions( void )

{ 

   printf( "Enter choice:\n"

          "1 to enter a student name stack\n"

          "2 to delete a student name stack\n"

          "3 to end program\n" );

}



void push( StackNodePtr *head, int info )

{ 

   StackNodePtr newPtr;



   newPtr = malloc( sizeof( StackNode ) );

   if ( newPtr != NULL ) { 

      newPtr->data = info;

      newPtr->nextPtr = *head;

      *head = newPtr;

   }

   else

      printf( "%d not inserted. No memory available.\n",

              info );

}



int pop( StackNodePtr *head )

{ 

   StackNodePtr tempPtr;

   int popValue;



   tempPtr = *head;

   popValue = ( *head )->data;

   *head = ( *head )->nextPtr;

   free( tempPtr );

   return popValue;

}



void printStack( StackNodePtr currentPtr )

{ 

   if ( currentPtr == NULL )

      printf( "The stack is empty.\n\n" );

   else { 

      printf( "The stack is:\n" );



      while ( currentPtr != NULL ) { 

         printf( "%s --> ", currentPtr->data );

         currentPtr = currentPtr->nextPtr;

      }



      printf( "NULL\n\n" );

   }

}



int isEmpty( StackNodePtr topPtr )

{ 

   return topPtr == NULL;

}